Transmission



E. A. THOMPSON TRANSMISS ION Filed April 15 1925 2 Sheets-Sheet 5] vwentoz:

Oct. 20, 1931. E. A. THOMPSON 1,827,960

TRANSMISSION Filed April 15, 1925 l 2 Sheets-Sheet 2 7%W/' Ma 7 WWW Patented Get. 20, 193 1 Y TRANSMISSION Application filed. April '15,-1925.' -'Seria1 1 Io. ,23,2 2 3. I

I My invention relates'to new and useful improvements in transmissions and has for-its principal object the provision of an overdrive whereby the driven shaft may be operated at s a greater speed than is ordinarily the ease when the driven shaft is directlyconnected to the drive -shaft, the overdrive being adapted foruse in connection with the well-known I V r v overdrive illustrated, in Fig. 3, and

form of transmission now commonly in use.

. Another object of the invention resides in the provision of a transmission in which the driveshaft and driven shaft are off center With respect to each 'other' and provid ng a coupling between members carried by eachof said shafts .wherebysaidshafts may :be connected for a,-direct.-drive "or for a drive through a train of gears.

A further ob'ect of the -.invention'consists in the provision of a transmission in which the drive shaft and thedriven shaft are elf center, one with respect to the other, and in which a freely rotatable member is carried by the driven shaft and driven at all times by the drive shaft." 1 j A still further object of the invention consists in the provision of" a' transmission in which the drivexshaft andthe driven shaft are off center, one with respect to the other,

and in -which affreely rotatable member is is no variation in the. angularrvelocity between the drive shaft and said member. As anotherobjectlprovijde anovel form from thezsame gear shift 'levernowcormnontransmission. 5

In the 'drawingslhave illust'rated; the pre- 1 :ferred embodiments of theinventibn as; they now appeart'o me and iii the I-following speciv :fication haveidescribed suchembodiments but I do not desire to limit myself to the particu- I v the. member lG having a reduced portion 17 providedwith' ,the"teeth 18 adapted to 'be 9 V I meshedwith the internal teeth .14 of the shiftlari arrangements disclosed anddescribed-but such changes may be made as i will fall; within the scope of the appendedclaims; i i

In the-drawings i Fig. 1I'is a longitudinal section, throughthe transmisslon' housing with parts. 111x1 shownxin'levationv g w 2 v5 vibration begins to be excessivein the maj or-. ity of veh1cles'when'thespeed of an engine is tion I have providedan improved form of creasing the speed of f the engine above the carriedbythe drivenysha'ft andadriven atall .critical.,point.f

Etimesby'the drive shaftg-andin whichthere of'overdrive which is. adapted to "be operated i ly; in use. for shift g'the gears of a standard V V I Y I ll being at alltimes inv mesh with a1gear12 carriedb'y the,drive shaft2.- Thefshiftable larged to form the housing 19, the outerend ofwhich is flanged as shown at .20, and. has I Fig.2 is rirsgmental longitudinal macal section through my improved formf'of s i r i g d Overdrive-with parts shown in elevation. I v v Fig. as is a view [similar to Fig. "1' of a .55

different form of the invention.

F .4. 1's a fragmental longitudinal vertical ectlon of'the improved form of coupling and The standard transmission as nowf comin use is adapted for] three forward speeds; ;na1nely,low; .intermediate fand high., the high "speed being. securedjby directly connecting the drive shaft anddriven shaft. .It has been'found, in practice, that increased above'a critical point in the majority of cars at a speed of about thirty'miles an hour... To overcome this objectionable condie overdrive inwhich the speedjof the vehicle may be substantially increased. beyond the critical point "above mentioned without in- In the drawings 1 indicates. the transmis-f sion housing, 2 thedrive-shaft, 3 thefdriven shaft andthe countershaft; the driven shaft having m ounted thereonthe shiftable power gears 5, 6 and 7', andthe countershaft hav- 35 .ing secured thereto the usual gear cluster ins.

cIudingIthe gears s, 9, 10. and'11'," the gear f gear 7 isprovidediwith theexternal teeth 13 and the internal teeth '14. 1.;

'able gear 7.

-- The inner end of the driveshaft Zis'ensecured thereto the member 21, by rivets'or Y other suitable fastenings 22, uponwhich is formed the gear 12 previously described.

The shiftable gear 13 and the member 16 are received within the housing 19 as quite clearly shown in Fig. 2 of the drawings. Tee'thi23are formed interiorly of the housing 19 and are adapted to bein'eshed with the exterior teeth 13 of the shiftable gear 7.

The member 16 is connected toand driven from the drive shaft 2 by means of the coupling links 24: of'the shape more particularly illustrated in Fig. Got the drawings. These links connecting the freely rotatable member 16 to the drive member 2 rotate said member .16 at all times with the drive member;

' gear 7 is moved so that the internal teeth 14; are meshed with the teeth'18 and'allow for an overdrive when the gear 7 is shifted so that the external teeth lgmesh with the teeth'23.

I will now describe the operation of the coupling whereby the torque is transferred from the drive shaft2 to the rotatable member 16 on the driven shaft 3 referring more particularly to Figs. 5 and-6. The serles of holes in the end of the housing 19 driven by the drive shaft 2 and equally spaced on the same diameterof circle with respect'to'the center 25of the drive shaft 2 as the holes in the rotatable member 16 are with respect to 'thecenter' 26 of the driven shaft 3." It will therefore be seen that the distancebetween f centers of the pins'27 and 27 of the link 24 is equalto the distance between the centers 25 and 26 of the two shafts and it will further beappa'rent' thatsin'ce the spacing of the holes in these members intowhich the and a driven shaft arranged 01f center one: with respect to the other, a 'housingcarried by the drive shaft, a normally freely. rotatable pins of the connecting links are received are of equal diameter with respect to" their respective centers that the distance between any two corresponding holes parallelto a line drawn through the axes 25 and 26 of the two shafts will beequal to the distance be- 1 tweenthe holes.

Therefore the angular velooity ofthe member 16 will at all "times be equal tothe angular velocity of'thehousing the jcenters 25 and 26 of the shafts and that .while the lines on'one side of the centers are action. 7

19. It will also be seen that a line joining the centers 27 and 27 of the'link 24 willat all times be parallel with a line passing through transmitting the torque by a pushing action the links on the opposite side of the center line are transmitting the torque a pulling An eccentric bushing 28 is providedin a L bridge 31 formed interiorly of the transmission housing 1 and the roller'bearings 29 are 7 received interiorly'in the bore of the bushing which is placed concentric with the center'of the driven shaft 3. Roller bearings 30 are 7 arranged exteriorly of the bushing for supporting the forward end of the drive shaft housing interiorly of the gear 12, the roller bushings beir'ig' concentric with the center line of the drive shaft 2. y

InFigs. 3 andit of the drawings I have illustrated a form of invention differing slightly from that form shown in Figs. 1 and 12. In the form of the invention shown in and 4 the gear 32 corresponding to the gear-12 inFig's. l and 2 may be mounted 7 Figs. o

on the drive shaft 2 at a point where the end of the driveshaft 2 isenlargedto'form the housing19. It will be understood that the gear 32wi11 at all timesbe in mesh with. the gear 11. Withthis construction I doaway with the member 21 which is secured to the end of the housing 19'as" shownin'Figs. 1 and 2- and indoing this I do away withthebearing which is shown 'in Figs. :1' and 2 as including the 'ec'centrio'bushing 28 and the associated roller bearingsand provide the bearing 33 mounted in one end of the transmission housing 1 and the-bearing 3 L. mounted interiorly of said housing 1. In'all other respects the form of 'theinvention disclosed in Figs. 3 and 4, and the operation thereof,is similar to that disclosed and described in Figs. 1 and 2. v

While my invention relates primarily to the provision of an overdrive for the conventional form of transmission it will be apparent that it can be used as a speed reduction gear and that theconstruction could also be used, with slightmodifications, where merely a two speed transmission or drive is desired;

' Having fully described my invention what i I claim as new'and desireto 'securehy Letters 1 Patent is: w

1. A transmissionincluding a drive shaft 2. A transmission including a drive shaft.

and a driven shaft arranged off center" one withrespect to "the other, a: normally freely rotatable member carried byfone of the shafts, pivotal means 'connecting the normally freely rotatable member with the other shaft whereby it is driven therefrom, a shiftable gear mounted on that shaft carrying thenormally freely rotatable member and adapted to be member for establishing a relative direct connection between the drive shaft and driven' shaft, and means carried by that shaft to which the normally freely rotatable member is connected adapted to be engaged with the shiftable gear for establishing a relative indirect connection between the drive shaft and the driven shaftr 8. A transmissionincluding a drive and a driven shaft arranged off center one with re- 7 Y spect to the other, a normally freely rotatable member carried on one of the shafts,pivotal means connecting said normally freely rotatable member with the other shaft to be driven thereby, a shiftable gear mounted on that shaft which carries the normally freely rotatable member and adapted to be engaged with the normally freely rotatable member for establishing a direct connection between the drive and driven shafts, and means carried by that shaft to which the normally free- 1y rotatable member is connected and engageable with the shiftable gear for establishing J a relatively indirect connection between the drive and driven shafts. I

4. A transmission including a drive and a driven shaft arranged ofl' center one with respect to the other, a housing carried by one i of the shafts and having internal teeth, a clutch member loosely mounted on the other shaft, link members positioned between the clutch memberand inner face of the housing, each of said link members including oppo- J sitely directed projections arranged off center, one of said projections being loosely received in an opening formed in the housing I and the other projection being received in an opening in the clutch member, and a member slidablycarried by that shaft on which the clutch member is loosely mounted, said slidable member being adapted for engagement with the clutch member to establish a relatively direct drive between the shafts or to be A engaged with the internal teeth of the housing to establish a relatively indirect drive between the shafts.

In testimony whereof I hereunto 'afl'ix my signature.

EARL A. THOMPSON. 

